The Pharmacology Core will measure drug and/or metabolite concentrations in biological fluids of AIDS patients using established or modified assays. New "state of the art" drug assays will be developed for which fundamental parameters such as specificity, sensitivity, reproducibility, and rapidity will permit pharmacokinetic studies with AIDS patients. Rigorous and continuous quality controls will be performed in order to provide objective data on the intra-day and inter-day precision and accuracy of each analytical method. This will be important for permitting quality methods for subsequent investigations. Sample libraries ("Master Data Inventory" notebook and computer files) will be developed so that all samples passing through the laboratory will be entered and stored in the registration system. Data generated in the Core Laboratory will be reported to ACTU investigators and NIH officials. Results of studies performed in the Pharmacology Core Laboratory will be presented at the ACTU meetings and subsequently published.